Histidine catabolism is a major determinant of methotrexate sensitivity

Nature. 2018 Jul;559(7715):632-636. doi: 10.1038/s41586-018-0316-7. Epub 2018 Jul 11.


The chemotherapeutic drug methotrexate inhibits the enzyme dihydrofolate reductase1, which generates tetrahydrofolate, an essential cofactor in nucleotide synthesis2. Depletion of tetrahydrofolate causes cell death by suppressing DNA and RNA production3. Although methotrexate is widely used as an anticancer agent and is the subject of over a thousand ongoing clinical trials4, its high toxicity often leads to the premature termination of its use, which reduces its potential efficacy5. To identify genes that modulate the response of cancer cells to methotrexate, we performed a CRISPR-Cas9-based screen6,7. This screen yielded FTCD, which encodes an enzyme-formimidoyltransferase cyclodeaminase-that is required for the catabolism of the amino acid histidine8, a process that has not previously been linked to methotrexate sensitivity. In cultured cancer cells, depletion of several genes in the histidine degradation pathway markedly decreased sensitivity to methotrexate. Mechanistically, histidine catabolism drains the cellular pool of tetrahydrofolate, which is particularly detrimental to methotrexate-treated cells. Moreover, expression of the rate-limiting enzyme in histidine catabolism is associated with methotrexate sensitivity in cancer cell lines and with survival rate in patients. In vivo dietary supplementation of histidine increased flux through the histidine degradation pathway and enhanced the sensitivity of leukaemia xenografts to methotrexate. The histidine degradation pathway markedly influences the sensitivity of cancer cells to methotrexate and may be exploited to improve methotrexate efficacy through a simple dietary intervention.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Ammonia-Lyases / deficiency
  • Ammonia-Lyases / genetics
  • Ammonia-Lyases / metabolism
  • Animals
  • CRISPR-Cas Systems / genetics
  • Cell Line, Tumor
  • Female
  • Folic Acid Antagonists / pharmacology
  • Folic Acid Antagonists / therapeutic use
  • Glutamate Formimidoyltransferase / deficiency
  • Glutamate Formimidoyltransferase / genetics
  • Glutamate Formimidoyltransferase / metabolism
  • Histidine / metabolism*
  • Histidine / pharmacology
  • Humans
  • Male
  • Methotrexate / pharmacology*
  • Methotrexate / therapeutic use*
  • Mice
  • Mice, Inbred NOD
  • Mice, SCID
  • Multifunctional Enzymes
  • Neoplasms / drug therapy*
  • Neoplasms / metabolism*
  • Nucleotides / biosynthesis
  • Reduced Folate Carrier Protein / genetics
  • Reduced Folate Carrier Protein / metabolism
  • Tetrahydrofolate Dehydrogenase / metabolism
  • Tetrahydrofolates / deficiency
  • Tetrahydrofolates / metabolism
  • Xenograft Model Antitumor Assays


  • Folic Acid Antagonists
  • Multifunctional Enzymes
  • Nucleotides
  • Reduced Folate Carrier Protein
  • SLC19A1 protein, human
  • Tetrahydrofolates
  • 5,6,7,8-tetrahydrofolic acid
  • Histidine
  • Tetrahydrofolate Dehydrogenase
  • FTCD protein, human
  • Glutamate Formimidoyltransferase
  • Ammonia-Lyases
  • Methotrexate